Rather then just getting complete acces to DRS and KERS at the apporpiate levels, I think it would be cool to be able to level it up. For example developmet level 3 would give you DRS lvl 1, development level 4 gives DRS lvl 2, and so on. And similiar for KERS.
Level 1 of course would be weaker than the current versions we have now, and there would be a max level.